rev 5/1/25

Chloroform production and use

Main properties

Molecular Formula  CHCl3

Molecular Weight   119.37 g/mol

Odor   Pleasant, etheric, nonirritating

 Boiling Point   61.12 °C

Melting Point   -82.3 °F    -63.47 °C

 Density (at 20 °C): 1.48 g/ml

Synonyms  

    67-66-3 Chloroform  Chloroforme (French)

    Formyl trichloride  Methane trichloride   Methenyl chloride

    Methenyl trichloride   Methyl trichloride   NCI-C02686  

 
Pure chloroform is light sensitive and reagent grade chloroform usually contains 0.75% ethanol as stabilizer



CHLOROFORM PRODUCTION

Chlorination of methane is well known with many patents taken by  various corporations since 1879 .The reaction which very exothermic is done in continuous  and give a mixture of diffferents chloroalcanes CHCl3, CH2Cl2,CHCl3,CCl4.....which are separated by distillation .The reaction is carried out between 200 et 500° c under pressure with short reaction  time (in the second range)  .

The reaction can also be done in liquid phase with the help of UV light (Photochlorination) .In this case conditions  are generally milder  e.g. temp 50°c pressure few bars.
 
It is also possible to get chloroform by dechloration of carbon tetrachloride  as mentioned  in  patent EP0460138B1    Published 1995-02-15

As the market of chloroalacanes is changing over the time the processes have to be flexible to fit production to the market


Here are some examples taken from a  very rich  patent litterature    .More details here


Vapor Chlorination of methane

US 3,126,419  CHLORINATION OF METHANE   assignors to Stauffer Chemical  Filed Sept. 26, 1960, Ser. No. 58,367

This invention relates in general to a process for the partial chlorination of methane and in particular to a process for maximum production of methylene chloride
and/or to chloroform via the chlorination of methane.




metahne chlorination


Chlorination of methyl chloride/methylene dichloride

EP0379754B1     E.I. Du Pont De Nemours   Priority 1987-11-10 • Filed 1989-01-24 • Granted 1994-03-23 • Published 1994-03-23

The chlorinated methanes (methyl chloride, methylene chloride, chloroform and carbon tetrachloride) are well-known articles of commerce and are generally prepared by chlorination of an underchlorinated raw material. As the demand for the individual members of the series varies from time to time, it is desirable to be able to control their production accordingly.

At present (1987)  the demand for chloroform is high, that for methylene chloride and carbon tetrachloride is low. The existing chlorination processes, however, are not entirely satisfactory for producing chloroform to the substantial exclusion of the other polychloromethanes. For example, the direct chlorination of methane for this purpose (described in SRI #126, C₁ Chlorinated Hydrocarbons, published August 1978, pages 49 to 96) is difficult to control and expensive to operate because of the necessity of recycling large amounts of methane, methyl chloride and methylene chloride. It also tends to produce undesirably high ratios of carbon tetrachloride to chloroform, which constitutes a cost penalty in view of the relatively low demand for the tetrachloride.

The production of methyl chloride is readily controlled by utilizing the reaction of hydrogen chloride with methanol, and for this reason it is an attractive starting material for the higher chlorinated methanes.

    CH3Cl + CH2Cl2  + Cl2 -------> CHCl3  +CCl4      Pressure 80 bars temp 200 to 500°c

chcl3 from CH3Cl dupont




PhotoChlorination of methyl chloride/methylene dichloride

  FR2568872B1  *  1984-04-27  1986-11-28  Atochem   CONTINUOUS PROCESS OF RADICAL CHLORINATION OF CHLOROALKANES

The chlorination of a mixture of  methyl chloride/methylen chloride can be done by activation of chlorine with UV lamps (photochlorination) in liquid phase .In this case  typical working condition are : temperature 44°c , pressure 4 bars  .Chloroform is the main product with small amounts de CCl4



CHCl3 photochlorination

CHCl3 by catalytical hydrogenation of CCl4

EP0460138  Priority 1989-12-22 • Filed 1990-12-13 • Granted 1995-02-15 • Published 1995-02-15


  CCl4  + H2 ------> CHCl3 + HCl
Catalyst Pd/Carbon  temp 160°C  pressure 3000 KPa
Ccl4 hydrogenation




CHCl3 from hexachloroacetone
Russia Patent  RU2206558C1   2003-06-20 Publication of RU2206558C1   
The method of producing chloroform by hydrolysis of hexachloroacetone at elevated temperature, characterized in that hexachloroacetone is hydrolyzed with water in the presence of ethanolamines as a catalyst at 95-150 o With simultaneous distillation of the reaction product - chloroform.


chcl3 from hexachloroacetone

Hexachloroacetone can be obtained by action of chlorine on ispropanol or better from acetone  in very good yield (>95%)  , catalysis by pyridine as depicted in China patent   CN109942392A (2022-01-21)


Vintage  processes

Chlorination of  methane (1879)

chcl3_from CH4_



decarboxylation  trichloroacetic Calcium salt(1928)

chcl3 from trichloroacetic calcium salt


Chlorination of carbonyl product


aceton_to_cHCl3






Electro Reduction of CCl4

Elctroreduction of carbone tetra chloride in mixture CCl4/EtOH/H2SO4  (US1534027 (1921)

chcl3 from cCl4

Chemical reduction of CCl4

US2104703A  Dow Chemical Co Priority 1936-02-13 • Filed 1936-02-13 • Granted 1938-01-04 • Published 1938-01-04
Patented Jan. 4, 1938 UNHTED S'E'AS Arm FFlE METHOD FOR. THE MANUFACTURE OF CHLOROFORM No Drawing. Application February 13, 1936, Serial No. 63,734 9 Claims. This invention concerns an improved method of manufacturing chloroform by reaction of carbon tetrachloride with iron and water. 

2CCl4 + 2H2O + 2 Fe --->FeCl2 + Fe(OH)2 + 2CHCl3

Reaction catalysed by various Pb salt


CHLOROFORM USAGE

In terms of scale, the most important use  of chloroform is to give monochlorodifluoromethane (HCFC-22  alias R-22),

    CHCl3 + 2 HF → CHClF2 + 2 HCl

The reaction is conducted in the presence of a catalytical amount of mixed antimony halides.

Chlorodifluoromethane , a colorless gas is better known as HCFC-22, or R-22, or CHClF2. It was commonly used as a propellant and refrigerant. These applications were phased out under the Montreal Protocol in developed countries in 2020 due to the compound's ozone depletion potential (ODP) and high global warming potential (GWP), and in developing countries this process will be completed by 2030.

R-22 still remain  a versatile intermediate in industrial organofluorine chemistry, e.g. as a precursor to tetrafluoroethylene  by pyrolysis (at 550–750 °C) , with difluorocarbene as an intermediate.

   
    2 CHClF2 → C2F4 + 2 HCl

Polymerization of tetrafluoroethylene produces polytetrafluoroethylene (PTFE) polymers such as Teflon , Fluon and many others 


Worldwide, chloroform is also used in pesticide formulations, as a solvent for lipids, rubber, alkaloids, waxes, gutta-percha, and resins, as a cleaning agent, as a grain fumigant, in fire extinguishers, and in the rubber industry.